. The surface area of a rectangular prism is 150 cm². If all the sides are tripled, what will the new surface area be?

Question

anonymous · Answer

A prism is three-dimensional, so it basically has three lengths somewhere that you're tripling.  If this were a rectangular box for example (v = LWH), then tripling would give you 
V = (3L)(3W)(3H)
V = 27LWH
V = 27v

This reasoning will work for any three-dimensional shape.  Basically, you are cubing the 3 to get 27.

radar · Answer

The answer provided by jabberwock is true for volume, however, this problem is about surface area, the new surface will be 9 times the old surface area as the surface is a squared function.  The new surface are will only be 9 times the old.  SA=1,350 SqCm.

anonymous · Answer

Oh, whoops.  Quite right, radar.  My bad.

radar · Answer

A very good explanation regarding volume.  I see problems asked about volume most of the times, this was an exception.

radar · Answer

Thanks for participating in OC.